There is increasing evidence which suggests that a close relationship exists between the herpes simplex virus type 2 (HSV-2) and cervical neoplasia. This association was further strengthened by a recent report in which an antigenic relationship was found between HSV-2, cervical cancer tissue antigen preparations, a cell culture derived from cervical cancer, and HSV-2-associated hamster sarcomas. However, attempts to characterize and elucidate the nature of these antigens have not been successful. The purpose of the proposed research is to employ rabbit antisera to two purified HSV-specific early nonstructural polypeptides (VP175 and VP143) and to a major HSV envelope glycoprotein (VP119) using the highly sensitive and specific immunoperoxidase technique as a probe to localize and characterize HSV-2-specific antigens in cervical biopsy tissue, in cell lines of cervical carcinomas passed in nude thymus-deficient mice, and in HSV-transformed hamster embryo fibroblasts. The anti-VP143 has been found to react by immunofluorescence with HSV-2 transformed cells. Goat anti-rabbit IgG will be digested with pepsin and reduced to Fab' fragments, which will be conjugated to peroxidase. Cell pellets, cell monolayers, cryostat sections, and appropriate controls will be incubated with rabbit anti-HSV polypeptide sera and treated with peroxidase-conjugated goat anti-rabbit Fab'. Samples incubated with peroxidase conjugates will be processed for the histochemical demonstration of peroxidatic activity.